The present invention relates generally to formation fracturing and gravel packing operations performed in subterranean wells and, in an embodiment described herein, more particularly provides a formation fracturing and gravel packing tool and associated methods for high flow rate slurry delivery.
Formation fracturing and gravel packing operations continue to utilize ever higher flow rates and volumes of slurry delivery. In typical operations, these high flow rates and volumes are detrimental to equipment used in the operations, since the slurries are usually very abrasive. This equipment abrasion has been mitigated in some instances by providing thicker cross-sections in the equipment, increasing flow area to reduce slurry velocity, using abrasion resistant materials, and smoothing slurry flowpath transitions.
As applied heretofore, however, some of the above techniques have had limited applicability in wells having relatively small bores. For example, the cross-sectional thickness of equipment cannot be increased where the equipment is already at its maximum allowable outer dimensions. Of course, internal flow passages may be reduced in order to increase the cross-sectional thickness of the equipment, but to do so would decrease the available flow area, resulting in increased slurry velocity for a given flow rate.
In addition, formation fracturing operations have begun to utilize man-made proppants which are very dense, hard and abrasive as compared to sand. Examples of these are marketed under the names Carbolite and Carboprop. The use of these and similar proppants makes it even more desirable to enhance the resistance of formation fracturing equipment to abrasion occasioned by high flow rate and high volume slurry flow therethrough.
It is accordingly an object of the present invention to provide such high flow rate formation fracturing and gravel packing equipment and associated methods of completing subterranean wells. It is also an object of the present invention to provide such equipment and methods in which a slurry flowpath is relatively unrestricted, is comparatively large for the size of the equipment, and which is relatively smooth. It is another object of the present invention to provide the equipment and methods such that their utilization is convenient and practical in application.